Drafting assembly or kit



E. H. MAY

DRAFTING ASSEMBLY OR KIT Feb. 27, 1951 Filed Feb. 9, 1948 JNVENTOR.

M N ilxllllllllllll|\l| llllllllllll l1 Ulnar \wm NM MN k mm 0 vNi Ev QMw llll nfi W M M w m T T A Patented Feb. 27, 1951 DRAFTING ASSEMBLY ORKIT Ellwood H. May, Rockford, Ill., assignor to EngineeringManufacturing00., Sheboygan, Wis., a corporation of Wisconsin Application February 9,1948, Serial No. 7,150

This invention relates to a drafting assembly or kit comprising adrafting board and an associated T square mounted thereon. An object ofthe invention is to provide an assembly of the above character withnovel means for retaining the draf ting board and the T square in anassembled relation so as to prevent accidental loss of the T squarewhile at the same time permitting theT square to slide relative to theboard as required by a user. f b r Another objectof the inventionis theprovision in an assembly of the above character having novel clampingmeans acting between the head of the T square andtheboard f orfrictionally securing the T square in a desired adjusted position on theboard. I I

Another object of the invention is to provide an b rof h sh re. ch r t wich. i simple in construction-and which is relatively inexpensive tomanufacture. H

Another object of the invention isto provide a drafting board and Tsquare assembly; of the above character which can be made in relativelysmall sizes for students and the like so that it is readily portable,which is always ready for use, and in which the board and T square are,held together as a unit so thatgit can be carriecl be tween classroomsor the like and theuser does not have to worry about the traight edgebecoming displaced fromthe board. y

Other objects and advantagesoi the invention will become apparent fromthefollowingdetailed description taken in connection with theaccompanying drawings, in which V,

Figure 1 is a bottom .plan view ofa drafting board and T square assemblyembodying the in.- vention, and d g A Fig. 2 is a side elevationalviewof the above assembly. I

Referring now to the drawings. the invention is shown embodied inaportable drafting board and T square assembly or unit. In general, thelatter comprises a drafting board Ii! with a- T square ll having'astraigh't edge blade I 2, extend:- ing across a fro'ntl3 of the boardill andmovable relative to the board as required by the user, At one end theblade l2.is attached to ahead I4 slidably engaging aside edge 1 6 of theboard and arranged to frictionally engage the board .to maintaintheblade l2 in' any desired position on' the front of the board..- l). df 1 j As shown inFig'ure, 1' the, drafting board H] is: rectangular inshape and comprises spaced sub stantially"straighil ip'arallel"side-edges" I and I II 3 Claims. (01. 33-80) I board may be formed fromany suitable material.

For purposes of illustration the board is shown in this instance asbeing formed from wood. The front [3 of the board is preferably formedwith a smooth surface for the reception of drawing paper or the like.

Provision is made for securing the T square II in an assembled relationwith the board ID in a manner which prevents accidental removal of theTsquare from theboard yet permits free movement of the blade l2 betweenthe top edge 18 and the bottom edge [9 of the board. For this purposesuitable clips 20 and 2| associated with opposite ends of the T squarell and engageable with aback [5- (see Fig. 2) of the board H] areutilized. As shown in Fig. 2 the clip 20, connected to the end of thestraight edge I2 away from the head I4, comprises a- U-shaped memberhaving spaced legs 22 and 23 connected together by a bridging member 24.The leg 22 is rigidly secured to the side of the blade away fromengagement with the paper receiving surface l3 as by a rivet 26 and theleg 23 is shaped to be received, in a rabbet 21, the purpose of whichwill presently appear, formed along the side edge I! of the board andopening on tothe side edge H and back [5 respectively. Th bridgingportion 24 spaces the portions 22 and 23 apart a distance correspondingto the combined thickness of the blade I2 and the thickness of ,theboard in at its side edge l7. Preferably the legs 22 and23 are spaced sothat there is a small clearance between the clip 20 and the edge of theboard.

The clip 2i as contemplated in this embodiment of the invention isformed by a plate 25 secured .to the side of the head [4 away from theblade l2 and shaped to be received in a rabbet 23, formed along the sideedge 16 of the board In and opening on tothe side edge I6 and back [5respectively. The thickness of the head It is substantially equal to thethickness of the board measured along the side edge l6 so that the plate25 flush with the back of the head is readily receivable in the rabbet.

An important feature of this drafting board and T square assembly is theprovision wherein the T square may be readily clamped in any desiredposition so that the blade I2 on the front l3 of the board 10 can belocated as required with respect to the drawingpaper. In this embodimentof the invention this is effected by a movable clamp 29 mounted on thehead M of the T square l liand shaped to beengageable with a shoulder3|. spaced from the side edge 15 of theboard against which the head 14abuts and a spring-32 3 disposed between the movable clamp 29 and thehead I4 urging the head into engagement with the side edge I6 and theclamp into engagement with the shoulder 3I. The movable clamp 29 asshown in Figures 1 and 2 is formed in part by the plate 25 which ismounted on the head M for relative movement and an upstanding flange 32integral with the plate 25 and shaped to abut the shoulder 3|. As bestshown in Fig. 2 the shoulder 3| is formed by one Side of a groove 33formed inwardly from the side edge I6 on the back I of the board I I]and intersecting the rabbet 28. To permit relative movement of the clamp29 with respect to the head I4, the plate 25 is formed with spacedelongated slots 34' through which screws 36 extend for loosely retainingthe plate 25 in position on the head I4. Washers 31 may. be disposedbetween the head I4 and the platev 25 to minimize friction between therespective parts.

While the spring 32 may take many different shapes and many suitablemeans may be employed for mounting the spring, as shown herein, thespring 32 comprises a U-shaped member disposed between the plate 25 andthe head I4 to effect a clamping action of the flange 32 against theshoulder 3I and the head I4 against the side edge I6. Thus, one end 38of the spring is anchored under a tab 39 formed from the plate 25 andthe other and M of the spring is received in an opening42 in a post 43rigid with the head I4. The post 43 projects through an elongated slot44 formed in the plate 25 and disposed between the spaced slots 34-.

As shown in this embodiment of the invention, the back I5 of the boardIn is formed with rabbets 2! and 28 adjacent the side edges I6 and Irespectively. This construction permits a central portion 46 of theboard In as seen in- Fig. 2 to rest on the fiat surface and the lowerportions of the clips and 2 I are raised sufiiciently from the flatsurface to permit free movement of the T square II on the board I0.

Means for limiting the movement of the T square II relative to the topedge I8 and bottom edge I9 of the board I0 is provided for preventingthe accidental removal of the T square II from. the: board I0. As shownin Figure-1' stops in the form of pins 41 are positioned at each end ofthe rabbets 21 and 28 respectively. Thus, when. the blade I2 is moved tothe top edge I8 of theboard the clips 20 and 2I engage the respectivepins 41 and prevent removal of the T square I I from the drafting boardII]. In a similar manner the stops 41 at the bottom edge I9 of the.board also prevent removal of the blade I2 when the latter is moved tothe bottom of the drafting board.

I claim:

1. In a portable drafting board and T square assembly, the combinationof: a drafting board having first and second side edges in spacedsubstantially parallel relation, the opposed faces of the board beingplane and forming a front working surface and a plane back, said boardhaving a rabbet of substantial depth along the first side edge openingon to the back and first side edge of the board, said rabbet including acut of greater depth than the balance of the rabbet located to form ashoulder spaced inwardly from and parallel to the first side edge of theboard, a T square comprising a head portion of substantially lesserthickness than the board having an edge shaped to abut against the firstside edge of said board, and a straight edge extending across and incontact with the front surface of the board having one end rigidlyattached to said head and the opposite end extending to the second sideedge of the board, a plate attached to the back of the head comprising afirst portion shaped to extend into said rabbet from the first edge ofthe board and a second portion in side by side relation with the back ofsaid head and having an elongated slot, means engageable; with saidsecond portion and extending through said slot for retaining said platein an assembled relation with said head, a flange integral with saidplate and; engageable with said shoulder, and a compression springacting between said plate and said head: for releasably urging the edgeof the head into Clamping engagement with the first edge of the boardand said flange into clamping engagement with; the shoulder, said plate,said means, Said flange and said spring being shaped and positionedwholly between planes defined by the front and back surfaces of saidboard.

2. In a portable drafting board and T square assembly, the combinationof, a drafting board having first and second side edges in spacedsubstantially parallel relation, the opposed faces of the board beingplane and forming a front working surface and a plane back, said boardbeing provided with rabbets of substantial depth along the first andsecond side edges'opening on to the back and side edges of the board,said rabbet along the first side edge including a cut of greater depththan the balance of the rabbet located to form a shoulder spacedinwardly from and parallel to the first side edge of the board, a T'square comprising a head portion of substantially lesser thickness thanthe board having an edge shaped to abut against the first side edge ofsaid board, and a straight edge extending across the front surface ofthe board having one end rigidly attached to said head and the oppositeend extending to the second side edge of the board, a clip comprisingspaced legs, means for securing one of said legs rigidly to saidopposite end of said straight edge against the front side thereof; theother legs extending intothe rabbet along the second side edge from theedge of the board forwardly of the plane defined by the back of theboard, a plate attached to the back of the head with respect thereto,said plate having a portion shaped to extend into said first rabbet fromthe first edge of the board and a second portion in side by side closelyspaced relation with the backof said head, said second portion havingaplurality of spaced slots, spaced headed members extending through twoof said slots for supporting said plate on said head for movement withrespect thereto, a post rigid with said head and extending through aslot disposed between said headed members, a flange integral with saidplate engageable with said shoulder, and a compression spring disposedbetween said post and said plate for-releasably urging the head intoengagement with the first edge of the board and said flange intoengagement with the shoulder, said plate, saidheaded members, said post,said flange and said spring being shaped and positioned wholly betweenplanes defined by the front and back. surfaces of saidboard.

3. In a portable drafting board and T square assembly, the combinationof, a drafting board having first and second side edges in spacedsubstantially parallel relation, the opposed faces of the board beingplane and forming a front working surface and a plane back, said boardbeing provided with rabbets, of substantial depth along the first andsecond side edges opening on to the back and side edges of the board,said rabbet along the first side edge including a cut of greater depththan the balance of the rabbet located to form a shoulder spacedinwardly from and parallel to the first side edge of the board, a Tsquare comprising a head portion of substantially lesser thickness thanthe board having an edge shaped to abut against the first side edge ofsaid board, and a straight edge extending across the front surface ofthe board having one end rigidly attached to said head and the oppositeend eX- tending to the second side edge of the board, a clip comprisingspaced legs, means for securing one of said legs rigidly to saidopposite end of said straight edge against the front side thereof, theother legs extending into the rabbet along the second side edge from theedge of the board forwardly of the plane defined by theback of theboard, a plate attached to the back of the head with respect thereto,said plate having a portion shaped to extend into said first rabbet fromthe first edge of the board and a second portion in side by side closelyspaced relation with the back of said head, said second portion having aplurality of spaced slots, spaced headed members extending through twoof said slots for supporting said plate on said head for move ment withrespect thereto, a post rigid with said head and extending through aslot disposed between said headed members, a flange integral with saidplate engageable with said shoulder,

stops disposed in said rabbets adjacent each.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 571,252 Walkinshaw Nov. 10, 1896611,697 Lundy Oct. 4, 1898 1,020,253 Blair Mar. 12, 1912 1,389,904Rudolph Sept. 6, 1921 2,332,967 Fatkin Oct. 26, 1943 FOREIGN PATENTSNumber Country Date 213,098 Germany Sept. 8, 1909 274,947 Germany June3, 1914

